Thread feed unit for double cylinder knitting machines

ABSTRACT

THIS DISCLOSURE RELATES TO A FEED UNIT FOR DOUBLE CYLINDER KNITTING MACHINES, COMPRISING A PLURALITY OF GUIDE SUPPORTS MOUNTED ABOUT A FIXED VERTICAL SHAFT FOR OSCILLATION BETWEEN A FEED POSITION AND A REST POSITION, A THREAD CARRIER MOUNTED ON EACH OF SAID GUIDE SUPPORTS FOR LONGITUDINAL TO AND FROM THE NEEDLE CYLINDERS, CABLE MEANS BEING ARRANGED ECCENTRIC TO SAID FIXED SHAFT FOR   CAUSING A THREAD CARRIER TO SLIDE AWAY FROM SAID NEEDLE CYLINDERS BEFORE THE OSCILLATION OF THE RELATIVE GUIDE SUPPORT TOWARDS THE RESP POSITION.

Sept. 20, 1971 F. LONATI 3,605,444

THREAD FEED UNIT FOR DOUBLE CYLINDER KNITTING MACHINES Filed April 14, 1969 3 Sheets-Sheet 1 7-79, 3a F791? F/gjc 3d P79. in

INVENTOR. FRA NCESCO LONATI AGENT Sept. 20, 1971 F. LQNATI THREAD FEED UNIT FOR DOUBLE CYLINDER KNITTING MACHINES Filed April 14. 1969 3 Sheets-Sheet 2 INVENTOR. FRANCE SCO LONATI AGENT Sept. 20, 1971 F. LONATI 3,605,444

THREAD FEED UNIT FOR DOUBLE CYLINDER KNITTING MACHINES Filed April 14, 1969 3 Sheets-Sheet 3 T, P/ 9.5 r9 11a. 25

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AGENT United States Patent O 3,605,444 THREAD FEED UNIT FOR DOUBLE CYLINDER KNITTING MACHINES Francesco Lonati, Via S. P010 11, Brescia, Italy Filed Apr. 14, 1969, Ser. No. 815,669 Claims priority, application Italy, Apr. 19, 1968, 15,496/ 68 Int. Cl. D041) 9/10, 15/58 US. Cl. 6614 4 Claims ABSTRACT OF THE DISCLOSURE BACKGROUND OF THE INVENTION The present invention relates to a liner feed unit for use on double cylinder knitting machines for the manufacture, for example, of mens stockings.

It is known that the feed units which are called liners comprise a plurality of independent thread holders which are displaceable in order to permit the automatic changing of the threads during the manufacture of the knitwear articles, particularly mens stockings and the like.

Said displacements occur in a manner such that, during the feeding phase, the front ends of the various thread holders occupy almost the same position relative to the cylinders. Consequently cam systems or rather complicated slides are usually provided in order to permit the positioning of the thread holders without the collision of one thread holder with another during the displacements from the work position to the rest position and viceversa.

Such systems of known type are generally of delicate :and irregular nature and the fabric is affected by undesired defects, especially in the thread changing zones.

SUMMARY OF THE INVENTION The main object of the present invention is that of obviating the disadvantages of the known systems by providing a liner feed unit which is of rational and, at the same time, simple structure so as to give rise to a more regular and precise working than the known types.

Another important object of the invention is that of providing a liner feed unit of ready application to double cylinder knitting machines of any kind.

According to the invention there is provided a liner feed unit for double cylinder knitting machines comprising a plurality of thread carriers displaceably mounted on a fixed support structure arranged adjacent the needle cylinders, said liner feed unit being characterized in that it comprises a plurality of guide support members for said thread carriers, said guide support members being independently and oscillatably mounted about a fixed, preferably vertical shaft, for movement from a rest position to a feed position and vice-versa, each of said thread carriers being mounted for to-and-fro longitudinal sliding on the respective support guide member and being associated to a repsective control body, such as a flexible tie-rod, fitted in an eccentric position with respect to said fixed shaft, means being provided for causing the moving "ice away in longitudinal direction, during the passage from the feed position to the rest position, of each of said thread carriers, with respect to the needle cylinders, substantially before the rotation of the relative support guide members towards the rest position.

BRIEF DESCRIPTION OF THE DRAWINGS Further characteristics and advantages of the invention will appear more clearly from the detailed description of a preferred embodiment of a liner feed unit according to the invention for double cylinder knitting machines, illustrated by way of example in the accompanying drawings, in which:

FIG. 1 is a perspective view of the liner feed unit wit all the thread holders in the rest position;

FIG. 2 is a plan view of the liner feed unit with one thread holder in the work position;

. FIGS. 3a, 3b, 3c, 3d and 3e show diagrammatically, and to a reduced scale, two thread holders of the liner feed unit in the respective successive positions assumed during the successive stages of the changing of a thread;

FIGS. 4 and 5 show plan views, in the' work position and the rest position respectively, of the device relative to the thread holder of an elastic yarn; and

FIG. 6 is a partial side view of the device of FIGS. 4 and 5.

DESCRIPTION OF THE PREFERRED EMBODIMENT With reference to such figures, the liner feed unit according to the invention comprises a block 1 formed by four thread holders 2, 3, 4, 5, and a device 6 for the movement of another thread guide 7 relative to the elastic yarn intended to form part of the elastic border of the stockings.

The device 6 is mounted adjacent the block 1 so that the thread carrier 7 is adjacent the other thread holders 2, 3, 4 and 5 in the rest position shown in FIG. 1.

When a thread is being worked, the relative thread carrier must be positioned adjacent the needle cylinders, as is the case with the thread carrier 2 in FIG. 2 rotated anti-clockwise and displaced forwards with respect to its length. In FIG. 2 the needle cylinders are diagrammatically indicated with the line 8.

The block 1 comprises a base plate or fixed support structure 9 on whose lower face there is secured a vertical connection pin 10, and on whose upper face there are secured two other vertical pins or shaft member 11 and 12 which are connected together at their tops by a beam 13. The upper pin 11 constitutes the rotation pivot for four support guide members 14, 15, 16 and 17 which have a substantially C-shape in plan view. Said support guide members 14, 15, 16 and 17 are arranged one above another and carry the thread carriers 2, 3, 4 and 5, respectively. More precisely, each of the members 14, 15, 16 and 17 is fast with a plate 18 which is rotatably mounted on said pin 11 and engages the end of a spiral spring 19 which is mounted on said pin 11 and whose other end engages the upper pin 21 (FIGS. 1 and 2). The springs 19 are coiled in manner such as to urge the thread carriers 2, 3, '4 and 5 towards the work position. That is to say the springs 19 tend to rotate the thread carriers anti-clockwise (with respect to FIG. 2) and push them towards the position of the thread carrier 2 shown in FIG. 2.

The exact work position of each thread carrier is determined by the engagement of the relative support guide member with an adjustable stop screw 20 which passes horizontally through the pin 12 (FIGS. 1 and 2). There are thus four adjustable screws 20 arranged on the pin 12 atdifferent heights corresponding to the four members 14, 15, 16 and 17.

Each of said members slidably supports a rod 21 on whose front side is secured the thread carrier proper 2, 3, 4 or by means of a clamp 22.

The rear position 23 of the rod 21 is bent at 180 so that its end 24 is parallel to the main portion of the same rod 21. The rod 21 is mounted for longitudinal sliding in corresponding holes provided in the arms of the said C-shaped member. The end portion 24 is also slidably mounted in a corresponding hole provided in one of said arms, so that each of the members 14, 15, '16 and 17 supports a rod 21 for to-and-fro sliding.

On each rod 21 there is secured a clamp 25 to which there is pivoted a projection 26 designed to engage the end of a relative flexible cable 27. The sheath of said cable 27 is secured to a vertical pin 28 secured to the base plate on fixed support structure 9.

Between the clamp 25 and the relative support guide member, a spring 29 is mounted on the rod 21 and tends to urge the rod forward against an adjustable screw 30 secured adjacent the bent portion 23, with the same guide support member. The maximum backward position is instead determined by a stroke end block 31 which is adjustably secured on'the end portion 24.

The members 14, 15, 16 and 17 further carry thread guides 32 which correspond to other thread guides 33 mounted on a support 34 fast with the pin 28 so that the various threads (not shown) reach the thread carriers 2, 3, 4 and 5 by passing through said thread guides 32 and 33.

The springs 29 are arranged to be less powerful than the springs '19 so that, during the phase in Which each thread carrier is moved away from the needle cylinders, the thread carrier initially displaces longitudinally and the relative spring 29 is compressed, and then the thread carrier rotates about the pivot 11 with the deformation of the spring 19.

The above-described movement is obtained by means of the traction which the flexible cable 27 exercises on the clamp 25.

When the thread carriers are in the rest position (FIG. 1) all the flexible cables 27 must be pulled backwards for a distance suflicient to cause the backward movement and rotation of said thread carriers.

The device 6 relative to the thread guide 7 is constructed in analogous manner and comprises a support guide member 35 for the rod 21 supporting the thread guide 7. Such rod 21 is formed similarly to those of the block 1 with a bent portion 23 and an end portion 24.

"The member35 also carries a thread guide 32 and the relative movement is determined by a flexible cable 27 which is connected to a projection '26 articulated to the clamp 25. The sheath of this cable 27 is secured to a pro jection 36 fast with the base plate 37 of the device 6. The fulcrum for the oscillations of the member 35 is formed by a pin or shaft member 11a whose lower end is secured to the base plate 37, while the relative spiral spring 19a engages, at one end, the plate 18 fast with the member 35 and, at its other end, another pin 12a which is fast with the plate 37 and carries an adjustable stop screw 20a.

The rod 21 of the device 6 also supports, adjacent the bent portion 23, a clamp 38 carrying a lower pin 39 arranged to engage the cam face 40 of an oscillating lever 41 pivoted on a pin 42 fast with the plate 37. The lever 41 is urged against an adujstable stop screw 43 by a spring 44. With such arrangement, during the backward movement of the thread carrier 7, the pin 39 engages the cam face 40 so that the thread carrier 7 is slightly displaced, as indicated in dotted lines in FIG. 4.

In passing from the rest position (FIGS. 2 and 5) to the work position (FIG. 4), the pin 38 engages the back of the cam face 40 (as shown in dotted lines in FIG. 5) so that the lever 41 is caused to rotate in clockwise direction (as indicated by the arrow in FIG. 5) and there is practically no obstacle to the advance of the thread carrier 7.

The Working of the liner feed unit according to the invention is as follows:

When a thread carrier has to be brought into the work position, the respective flexible cable 27 is released so that the action of the springs 29 and 19 can take place. Since the action of the spring 19 has a greater force than that of the spring 29 during the initial slackening of the flexible cables 17, the members 14, 15, 16 and 17 rotate in anti-clockwise direction (with reference to FIG. 2) while, in the successive slackening phase, the rods 21, or rather the thread carriers displace longitudinally. The movement may readily be understood by comparing in FIG. 2 the position of the thread carrier 2 (working adjacent the cylinders 8) with that of the thread carrier 3 (in rest position). The movement of the rear portion of the rod 21 carrying the thread carrier 2 is indicated with dotted lines in FIG. 2.

When it is desired to remove the thread relative to the thread carrier '2 from the working position the inverse movements have to be carried out by pulling the cable 27 concerned. By pulling such cable 27 there initially occurs the longitudinal backward movement of the thread carrier 2, with the compression of the spring 29, and, successively, the clockwise rotation of the thread carrier 2 about the fulcrum 11 against the action of the relative spring 19. The achievement of the two separate phases of longitudinal displacement and rotation of each thread carrier is necessary in order to avoid collision between the front portions of the various thread carriers, which would impede any displacement.

The control of the cables 27 is determined by suitable cams (not shown) which are arranged so as to obtain the desired sequence of movements.

In FIGS. 3a to 3e there are diagrammatically shown the successive positions of the thread carriers 2 and 3 during a change of thread. More precisely, there is shown the movement for replacing in the working position the thread passing on the thread carrier 2 with the thread passing on the thread carrier 3.

For such purpose, firstly the cable 27 relative to the member 15 is released so that the latter rotates, during the first phase, about the fulcrum 11 so as to carry the thread carrier 3 into the position shown in FIG. 3b, while, in the successive phase, the further slackening of the released cable 27 causes the thread carrier 3 to move longitudinally towards the cylinders 8. The position of FIG. 3c is thus reached in which both the thread carriers 2 and 3 are in the work position.

Immediately afterwards the command is given for removing the thread passing on the thread carrier 2 from the working position. Thus the relative cable 27 is pulled so that the thread carrier 2 (FIG. 3d) moves backwards and subsequently rotates clockwise about the fulcrum 11 (FIG. 3e). There consequently remains in working position the thread passing on the thread carrier 3, while the thread passing on the thread carrier 2 is excluded from the working position.

The various thread carriers are carried, in the work position, into approximately the same point, the adjustment being possible by means of the screws 20 and 30.

The working of the device 6 relative to the thread carrier 7 for elastic yarn is completely similar to that described above.

In the case of the elastic thread, it should be borne in mind that the normal feed position, in which the thread is knitted, is only reached during the initial and final phases of the formation of the elastic border. During such phases the thread carrier 7 has to be arranged as shown in continuous line in FIG. 4, that is with the cable 27 completely slack.

Between the initial and the final phases, the elastic thread must simply be interlaced without being knitted by the needles. Consequently the thread carrier 7 must be slightly displaced backwards, as indicated with dotted lines in FIG. 4. In order to obtain such positioning, the relative cable 27 is pulled for a short distance so as to carry the pin 39 of the clamp 38 into engagement with the cam face 40 which causes the desired sideways displacement (position shown in dotted lines in FIG. 4). The thread carrier 7 remains in this position throughout the formation of the elastic border and is once again caused to approach the needle cylinders 8 (position shown in continuous line in FIG. 4), by completely releasing the cable 27, in order to obtain the knitting of the elastic thread during the final phase of the formation of the elastic border. The thread carrier 7 must then be displaced into the rest position (indicated with continuous line in FIG. by completely pulling the relative cable 27, in order to exclude the elastic yarn from the working position.

When the elastic yarn is required once again, the thread carrier 7 will be displaced to approach the needle cylinders (position shown in continuous line in FIG. 4) by passing through the position (shown in dotted lines in FIG. 5) in which the pin 39 engages the rear of the cam face 40, causing the clockwise displacement of the lever 41.

As may be noted, the movement of the various thread carriers, with the liner feed unit according to the invention, is obtained in very rational and simple manner, practically with a single slackening or tightening of the various flexible cables 27.

The invention as thus conceived may be subject to numerous modifications and variations all lying within the scope of the inventive concept.

Thus, for example, the number of thread carriers may be varied as desired.

In practice the materials employed and the dimensions may be varied according to needs and, moreover, all the members may be replaced with other technically equivalent means.

The term liner or liner feed unit as used in the foregoing specification and appended claims should be considered equivalent to the term striper or striper feed unit.

I claim:

1. In a double cylinder knitting machine, having upper and lower needle cylinders, a thread feed unit comprising a fixed support structure arranged adjacent said upper and said lower needle cylinders, a fixed vertical shaft member mounted on said fixed support structure, a plurality of support guide members carried on said shaft member and capable of oscillating thereabout in an independent manner from one another thus moving from a rest position to a feeding position and vice-versa, a plurality of rod-like thread carriers mounted lengthwise slidable on said support guide members towards and away from said needle cylinders, control means for actuating said support guide members and said thread carriers causing the sliding movement of said thread carriers on said support guide members towards the needle cylinders during the passage from the rest position to the nature position substantially after the oscillating movement of said support guide members and vice-versa, wherein, according to the improvement, each of said thread carriers further comprises a first spring means wound on each said thread carrier and having one end fast with said thread carrier and the other end in engagement with the relative support guide member, said first spring means being compressed during the backward movement of the said thread carrier from the working position to the rest position, and a second spring means wound on said shaft member and having one end in engagement with said support guide member and the other end fast with said fixed shaft member, said second spring means pushing said support guide member towards the feeding position against the action of said control means and having an elastic force greater than that of said first spring means.

2. A thread feed unit according to claim 1, wherein each of said support guide members has a substantially C-shaped form and is provided on its respective arms with holes in which the relative rod-like thread carrier is slidable.

3. A thread feed unit according to claim 2, wherein said rod-like thread carriers have each two adjustable stroke end projections for engagement with the relative support guide member.

4. A thread feed unit according to claim 1 further comprising a unit for feeding elastic yarn, having a fixed base plate, a vertical shaft member mounted on said base plate, a support guide member carrier by said shaft member and capable of oscillating thereabout from a rest position to a feeding position and vice-versa, a rod-like thread carrier mounted lengthwise slidable on said support guide member, control means for actuating said support guide member and said thread carrier, a pin mounted on said rod-like thread carrier, an oscillating lever arranged on said base plate, a cam face carried by said oscillating lever and engaging said pin, for causing at desired intervals the said thread carrier for elastic yarn to be positioned slightly displaced from the needle cylinder, thus placing the elastic yarn in the fabric being formed without the knitting of the elastic yarn.

References Cited UNITED STATES PATENTS ROBERT R. MACKEY, Primary Examiner U.S. Cl. X.R. 66-133, 139 

